I have an 89 2.3l ranger that never seems to warm up. The outside temperature is around 30 degrees here but even after driving the truck for about 10 to 15 minutes the temp gauge just barely comes off the C. Also the air from the heater is cold as well. I replaced the coolant and thermostat recently and everything looked ok.

I cant seem to figure out what could cause this, if the heater core wasnt working the gauge would at least read normal. And if the gauge of temperature sensors werent working the air would be hot after a short drive. And the water pump is good and lines are clear or else the truck would be overheating.

Any help or suggestions are appreciated.

 

If you have enough coolant, the only thing I can think of is that your thermostat is stuck open.

 

Which is what I thought too. But after replacing that and having the same exact problem it leads me to believe its something else im missing.

 

My friend just replaced the thermostat on his Mazda 2.3L(05) and it didn't help his.He's having the same problem.
I feel bad because I suggested that is what it was but ,then again I changed it for him.That's what friends are for.

 

Its nice to know im not alone with this problem. Let me know if he figures anything out.

 

Pull the thermostat out and put it in some boiling water on the stove. If you don't have a thermometer that reads high enough, watch for the little bubbles and see if it stays shut or open even to the point of boiling.

If your gauge is wrong (temp) see if your radiator hoses are getting warm. If they are, then there may be a valve that controls water to the heater core. If no valve, your heater core may be plugged up. I recommend a flush and then refill with new anti-freeze.

I really do help you find out what it is. When you do, please post it just in case someone else runs into this problem.

 

Thanks for the tips. Ill try pulling it out this weekend and see what it does. I know its rated for 195 which is what the truck needs but ill test it either way. Also another question, If I have a line plugged up or the pump is not working to its full potential would the temp gauge read high or low? Im not sure where they are positioned on the motor and if they read the coolant or actual engine. If they read coolant only I would make a guess that i have a plugged line or pump. If they read actual engine temp I really dont know whats wrong.

Thanks again!

 

Something about Rangers and thermostats. I put two in my truck recently and the second one worked. One other thing, make sure the thermostat is pushed back and seated well in the housing. If the housing is not clean and the thermostat not seated all the way back, water will seep around the thermostat.

 

its a 4 banger it takes time to get warm

 

Definitely check for trash in the system. If a line was plugged it would get hot because the coolant isn't circulating. Sounds a lit like a stuck thermostat

 

Im gonna go with water pump. Impellers could be rotted off and just has enough force to keep engine "cool". The temp sensors are inline with the heater core circuit, so if the water pump is too week to push coolant through the heater core, the coolant becomes stagnant, thus not much of a temp increase.

 

I have a 94 b2300 with 220k +, my temp guage has never worked right. It barely reads above C when warm. A couple months ago my heater stopped blowing warm air, and my engine began over heating when idling. I bought a new thermostat, but decided to try flushing my radiator first when I saw what a pain the *** it was to get to the thermostat. Now my heater blows hot again, and my truck stopped over heating.

 

I'm also having a similar problem to a degree. my temp guage is not reading right most of the time. it takes a while for it to warm up via the guage though it is about thirty or below out side but even before it got cold it took a while. but the heat blows warm. I'll be driving and eventually it goes up but when I gas it a little whilst driving it will drop and take a while to rise to normal. I have a new water pump newer antifreeze the hoses get warm, nothing over heats still drives fine just worried about the fluctuating temp guage.

 

My 99 XLT 4.0 temperature gauge has stopped working. Check engine light came on. Diagnostic said to replace engine coolant sensor. Now the heater is starting to blow warm air but not hot air. Could it be the thermostat

 

I have the same issue with my Ranger. It will warm up but as soon as I start moving and air flows over the rad it cools right down to COLD.

 

Was there ever a resolution to this? I’m currently having the same issue in my 94 2.3 L ranger.

 

Welcome to the forum

The 2.3l SOHC Lima engines don't generate much heat, in cold weather its good to put some cardboard in front of radiator to keep cold air from coming in to engine bay
Start by covering at least 1/2 the radiator and go up from there

But First check if thermostat is working
Start cold engine and feel upper radiator hose at the radiator, should be cold of course
Let engine idle for 3 or 4 minutes
Feel upper hose again AND feel heater hose
Heater hose should be warming up
Upper rad hose should be COLD, if upper rad hose is heating up like heater hose then thermostat is NOT working, its stuck open, needs to be replaced, use 190 to 195degF replacement, there are also 205-210degF replacements for these 2.3l Limas for use in northern climates

If temp gauge is going up to 1/3 to 1/2 then thermostat is working but if you have no heat in the cab then heater core is most likely clogged
Its easy to change on a 1994 Ranger and not expensive, 4 screws and 2 hose clamps

 

I found this thread and think there is a mystery with the 2.3l engine. The temp gauge stays way over in the cold area of the gage. Always ran cold since I bought the Ranger in 1994. Today I replaced the thermostat, gasket and housing even though the old tstat worked fine in a pot on the stove. The Ranger still is cold after running 25 minutes. By cold I mean 115 degrees F. That's enough for my winters here in NC but I suspect my engine is not functioning normally at that temp.
I read this thread and just maybe someone has THE answer. I see a lot of theories.
I even clamped off the top radiator hose and no hotter temp!
I just don't understand what could be wrong. But the Ranger runs perfectly otherwise. My mileage is 22 mpg.
Opie

 

Not theories for the most part
The 2.3l Lima engine is built like a tank, weighs in at over 400 pounds, heavier than some V8s
So there is alot of metal to warm up and keep warm, so it bleeds heat
This is why blocking off air circulation in engine bay can help, i.e. cardboard in front of radiator
Less air flow around block and head means they can retain more heat

Water cools much better than "coolant/anti-freeze", so running 70/30 mix, coolant/water, can keep engine temp higher, less cooling ability with less water

190degF Thermostat means upper radiator hose should never warm up from coolant flow if engine coolant is staying under 180degF
So if upper rad hose is warming up then there is an issue with new thermostat
In winter months a 2.3l Lima's radiator may never be used

The 2.3l temp gauge does stay on the cooler side because of the Senders location, its at the rear drivers side of engine, instead of the top front near thermostat housing like on most engines, but still should get up past 1/3 after 5 to 10 minutes of warm up
The top front of an engine is the hottest point for coolant flow, which is why thermostat is located there

 

Rond,
Thanks.

The engine stays cool.... maybe that's good. But I studied the 2.3l thermostat and housing a long time today. The thermostat fits very loosely in the housing when it is in your hand. There is a small rubber grommet around it. It seems to bottom-out metal-to-metal when you fit it in the housing by hand. Then there are two micro-flanges that I think are supposed to get caught between the tstat housing and the block when tightened and force the tstat to mate properly. Add to that scenario the fiber tstat washer for the housing to the block, I surmise that the tstat is not sealing. I proved that the tstat was functioning in hot water then put water in the housing over my sink while pushing down on the tstat against its grommet onto the housing. I plugged the heater's small bypass pipe with a fiinger. Big leak!!!! I could not get the tstat to seal. But the tstat itself was sealing great by way of observing the puddle of water in the tstat when I held it cold with a bit of water on it over the sink. So, my theory is the design of the housing and tstat does not seal well and allows bypass water to upper hose. I proved that by starting the engine cold with the upper hose off of the radiator. Water POURED out of the hose from the water pump. A good tstat can't seal if it is not mated in the housing!!! I am thinking of going with an inline tstat. Any thoughts? See pic.

 

Can anyone do this test for the benefit of science? Have someone start your Ranger from cold while you are standing in view of the engine hoses and after you have disconnected the upper hose from the radiator and let it hang down a bit. It will only take a few seconds to find out if water gushes out of the upper hose or not. Signal the driver to turn off the Ranger to minimize antifreeze loss (some will have been lost from upper hose when you disconnect it.).
When I did this test, I immediately saw a strong flow from the upper hose. From what I know, no flow should occur from the upper hose when the engine is cold and the thermostat is closed. This happened just I installed a new thermostat, gasket and entire new thermostat housing. My theory is that the design of the housing and thermostat sometimes allows the thermostat to "rattle" around and not fit snugly, thus allowing water to bypass, even when the thermostat is closed.
Thanks.

 

Coolant will come out upper rad hose, but very little if thermostat is closed
Most thermostats have a hole in the plate that allows trapped air and a little coolant to flow out all the time

Better test is to start cold engine and feel upper rad hose and heater hoses
Wait a few minutes and feel then again
Heater hoses should be getting HOT
Upper rad hose should still be cold
If upper rad hose is heating up as well then thermostat is letting way too much coolant out

 

Water is bypassing my thermostat. I am thinking of buying an in-line thermostat that I see on the web. It mounts securely on upper hose. Then I will take out the original thermostat from the housing.

 

I just saved myself money on my crazy idea of an inline thermostat.
I went to the Ranger and completely clamped off the upper radiator hose, so no water was leaving the engine. I used a heat infrared gun all over to monitor temperatures. After 25 minutes, my readings were 500 degrees at exhaust manifold, 100 degrees (+ or -) on left and right side spark plugs, 90 degrees on water pump housing. Inside cab temperature gauge, fully cold indicator. My book says the gauge registers from 100 to 250, cold to hot, so it make sense it hasn't moved. So, the thermostat is NOT the issue here. It seems to be just a cold running engine. Always has....... The 90+ degrees has always kept me warm in the cab in my mild (NC) climate so I am just getting a wild hair here to even worry about it??? I guess I am just curious all of a sudden. And perhaps my mileage is suffering with a cold engine. The forum here is full of owners with cold engines. Should I grin and forget it? Anyone want me to try something else? I am retired with too much time on my hands.

 

I bought into the mystery of why the Ranger 2.3 lima reads cold water temp all of the time. Experts like RonD clearly stated the engine is built like a tank and creates little heat. But, I had to go a step farther to see for myself. So I built onto a small temperature sensor-microprocessor board and used an app to see the temp on my smartphone inside the car as I drove or ran the engine in place. I used a 10k thermistor that was quick response. I placed the tiny sensor directly against the driver side of the engine block to duplicate closely the Ranger temperature sender there.
Results:
1. before start - gauge white pointer below the "C" marking on the inside Ranger instrument gauge. Actual temp = 67 deg F
2. start and idle 10 minutes - gauge pointer in middle of white pointer. Actual temp = 122 deg F
3. idle 20 minutes - not much pointer change. Actual temp 127.
4. drove Ranger 5 miles and back home. Gauge pointer just at the upper edge of "C" marking. Actual temp = 137 deg F. This was my max temperature.
5. got home. Idled for a while. Temp went to 122 deg F.
6. clamped the upper hose off tightly. No water flow to the radiator. The temp did not change. 122 deg F.
7. used rolled-up cardboard to stop the cooling fan from turning. The temp did not change. 122 deg F.

Conclusion: RonD is right. The 2.3 lima engine is a cool one. I can do another test one day to see how the gauge would read if I take out the sender from the block and stick it into a pot of boiling water. But, needless to say, I won't worry anymore unless the gauge gets to the middle or beyond of instrument gauge.

The images below show some info that I used.
Crazy idea, but unless it was a brutally hot day, I wonder if I could run the Ranger without the radiator and fan altogether? haha It sure looks like the thermostat will hardly ever open at all in my 2.3 lima.
On edit, I wanted to say that when I placed my thermistor tightly against the Ranger temp sensor that is on the heater hose near the water pump, the temperatures were about 9 degrees cooler across the board. I had my inside heater adjustment closed, but I think the Ranger allows trickle flow through the off heater so that the sensor will get hot correctly.


typical readout display on my smartphone inside Ranger cab with engine running, hose clamped shut.



Clamp on upper hose


gauge movement